Reclamation of arid and semi-arid soils: The role of plant growth-promoting archaea and bacteria

Arid and semi-arid soils are characterized by nutrient deficiency and water scarcity, declining soil quality and climate regimes that are unfavorable for crop production. These environments are also affected by other inherent abiotic and biotic factors that affect the structure and function of these ecosystems. Numerous factors influence nutrient availability, plant productivity in an arid and semi-arid environment. One influential factor is the soil rhizospheric microbial community, which is an integral part of the terrestrial ecosystem. With climate change already affecting crop yield in drylands, the potential role of these organisms in land restoration for enhancing plant productivity needs to be exploited. Maximizing the rhizospheric microbial functions in these agro-ecosystems is essential in the reclamation of arid and semi-arid lands for optimum productivity in a wide range of environmental perturbations. In this review, we present the applications of rhizospheric plant growth-promoting (PGP) archaea and bacteria in the solubilization of nutrients, production of growth regulators, carbon sequestration, competitive exclusions of pathogens, and remediation of arid and semi-arid soils.